Mismatched face for closing tags of jsx syntax in emacs 27.0.50

[mallt]

The closing tags of the new jsx syntax support in emacs 27.0.50 are shown in the rainbow-delimiters-mismatched-face:

This is the cursor position info:

             position: 55 of 106 (51%), column: 15
            character: > (displayed as >) (codepoint 62, #o76, #x3e)
              charset: ascii (ASCII (ISO646 IRV))
code point in charset: 0x3E
               script: latin
               syntax: )    which means: close
             category: .:Base, a:ASCII, l:Latin, r:Roman
             to input: type "C-x 8 RET 3e" or "C-x 8 RET GREATER-THAN SIGN"
          buffer code: #x3E
            file code: #x3E (encoded by coding system undecided-unix)
              display: by this font (glyph code)
    xft:-SRC-Hack-normal-normal-normal-*-24-*-*-*-m-0-iso10646-1 (#x2F2)

Character code properties: customize what to show
  name: GREATER-THAN SIGN
  general-category: Sm (Symbol, Math)
  decomposition: (62) ('>')

There are text properties here:
  face                 (rainbow-delimiters-mismatched-face)
  font-lock-multiline  t
  fontified            t
  js-jsx-syntax-table  (5)
  syntax-multiline     t
  syntax-table         (5)

Does anyone know how to fix this? Thanks!

[Fanael]

This looks like a problem with jsx syntax support, does the syntax-table property on the opening angle bracket correctly specify the matching closing bracket? Because the one on the closing bracket doesn't, the matching character is specified as nil here.

[mallt]

This is the cursor position info of the opening angle bracket:

             position: 52 of 106 (48%), column: 11
            character: < (displayed as <) (codepoint 60, #o74, #x3c)
              charset: ascii (ASCII (ISO646 IRV))
code point in charset: 0x3C
               script: latin
               syntax: (    which means: open
             category: .:Base, a:ASCII, l:Latin, r:Roman
             to input: type "C-x 8 RET 3c" or "C-x 8 RET LESS-THAN SIGN"
          buffer code: #x3C
            file code: #x3C (encoded by coding system undecided-unix)
              display: by this font (glyph code)
    xft:-SRC-Hack-normal-normal-normal-*-24-*-*-*-m-0-iso10646-1 (#x2F9)

Character code properties: customize what to show
  name: LESS-THAN SIGN
  general-category: Sm (Symbol, Math)
  decomposition: (60) ('<')

There are text properties here:
  face                 (rainbow-delimiters-depth-2-face)
  font-lock-multiline  t
  fontified            t
  js-jsx-close-tag-pos 97
  js-jsx-syntax-table  (4)
  js-jsx-tag-beg       (open . 57)
  syntax-multiline     t
  syntax-table         (4)

So indeed it seems no matching char is specified. I will report this in the emacs bug tracker.

Thanks a lot!